CVE-2026-89963 powerpc/kexec_file: Fix null-ptr-def in extra size calculation
A null pointer dereference in the Linux kernel's kexec_file module can cause a kernel panic, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-89963?
CVE-2026-89963 is a vulnerability in Linux, published on 16 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
powerpc/kexec_file: Fix null-ptr-def in extra size calculation
A static Sashiko AI review identified a potential NULL pointer dereference in kexec_extra_fdt_size_ppc64().
On platforms without any reserved memory regions, get_reserved_memory_ranges() can return 0 while leaving 'rmem' unallocated as NULL. Passing it directly leads to a kernel panic when evaluating 'rmem->nr_ranges'.
Add a NULL check for 'rmem' to prevent this crash.
Which versions are affected by CVE-2026-89963?
How do I fix CVE-2026-89963?
Apply the vendor's patch.
Is CVE-2026-89963 being exploited?
There is no known exploitation of CVE-2026-89963 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-89963, DEBIAN-CVE-2026-89963, GHSA-57qc-5c9v-2jq5, UBUNTU-CVE-2026-89963.